The 05 doesn't require premium either. The manual states, minimum octane 87, for better performance, use 91. I dont understand, the 05 and the 06 have the same engine, the 06 requires premium and the 05 does not. The 06 4runner V8 has the same engine, but it does not require premium either.
I just try out the 1st tank of 87 yesterday, so far so good, didnt notice much difference.
We got an 07GX a few weeks ago. The first couple of fill ups were with 91 octane California gas. Since the car is basically a people mover, performance is not as high a concern. I'm planning on switching to 87octane full time. Any problems at all with 87octane?